JPH07208316A - Impulse water turbine - Google Patents

Abstract

PURPOSE:To improve the efficiency of a impulse water turbine by forcing collision of water along the whole circumference of a runner. CONSTITUTION:A runner 13 is fixed to a rotatable rotary shaft 11 through a bearing 12, and a circumferential flow passage 14 is formed around the rotary shaft 11 by a casing 15. Discharging flow passages for discharging water from the inner side of the circumferential flow passage 14 toward the blades 13a of the runner 13 are formed at equal intervals in circumferential direction by a stay vane 21 and a guide vane 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impulse turbine and has an improved basic structure.

[0002]

2. Description of the Related Art One of the impulse turbines is the Targo Impulse turbine. The Targo Impulse turbine is configured as shown in FIG. A right end of a rotating shaft 1 which extends horizontally and is rotatably supported via a bearing 2 is interlocked with a generator 3, and a runner 4 provided with a plurality of radially extending blades is attached to the left end.

Iron pipes 5b, 5c for branching the water and flowing it horizontally are connected to the iron pipe 5a for flowing water from a high place to a low place, and the iron pipes 5b, 5c are guided to the inside of the case 7. ing. A nozzle 6a for ejecting water toward the upper portion of the runner 4 is provided at the tip of the iron pipe 5b, and a nozzle 6b for ejecting water toward the lower portion of the runner 4 is provided at the tip of the iron pipe 5c. There is. Then, inside the nozzles 6a and 6b, a cone-shaped needle is moved along the axis to increase or decrease the cross-sectional area of the holes at the tips of the nozzles 6a and 6b, thereby discharging water per unit time. Means are provided for controlling the.

In such an impulse turbine, two nozzles 6a,
Since water is sprayed from 6b toward the runner 4, more water can be converted into energy, and the nozzle 6a,
Since 6b is located symmetrically with respect to the rotating shaft 1, no unbalanced load is applied to the rotating shaft 1.

As shown in FIG. 4, when the two nozzles are provided, the maximum value of the cross-sectional area of the water jetted is that the inner diameter of the nozzles 6a and 6b is circular. S = (1/4) πd ² × 2. The amount Q ₁ of water jetted from the two nozzles 6a and 6b is determined by the flow velocity of water being V
Then, Q ₁ = (1/4) πd ² V × 2, and when the average diameter of the runner is D, D / d is only about 4.5, so d = D / 4.5 By substituting, Q ₁ = (1/4) π (D / 4.5) ² V × 2≈0.007757D ² V (1) Here, if the effective head of water is h, the flow velocity of water is V
Can be expressed as V = √ (2gh).

Although FIG. 4 shows the case where the number of nozzles is two, there is a case where there is one nozzle.

[0007]

However, there are only two parts of the runner, which are exposed to water, above and below the rotary shaft, and the entire runner is not effectively used along the circumference of the runner. There is no use because there is no Further, since water is injected from both sides of the runner to the runner, a lot of space is used for arranging the iron pipes, and as shown by W in FIG. 4, the area occupied by the impulse turbine is large. Even if the number of nozzles is single, since the iron pipe is large and protrudes in the horizontal direction, the occupied area is still large.

[0008] Therefore, an object of the present invention is to provide an impulse turbine that solves the above problems.

[0009]

The structure of the present invention for attaining the above object has a structure in which a runner is fixed to a rotary shaft rotatably supported by a bearing, and falling water rotates around the rotary shaft. It is characterized in that a circumferential flow path is formed so as to flow through the circumferential flow path, and discharge flow paths for discharging the water flowing through the circumferential flow path toward the runner are formed at substantially equal intervals around the rotation axis.

[0010]

The water flowing from a high place goes around the rotation axis by flowing through the circumferential flow path, and is jetted toward the runner from the discharge flow path while rotating. Since water is injected from the entire circumference to the runner, a large amount of water collides with the runner,
The efficiency of the impulse turbine can be increased.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

The construction of the impulse turbine according to the present invention is shown in FIGS. A rotating shaft 11 extending in the vertical direction is rotatably supported via a bearing 12, and a runner 13 having a plurality of blades 13a extending in the radial direction is fixed to the lower end of the rotating shaft 11, while the upper end of the rotating shaft 11 is It is linked to a generator (not shown).

A casing 15 forming a circumferential flow passage 14 is provided to guide water falling from a high place so that the water is jetted to the blade 13a of the runner 13 while rotating around the rotary shaft 11. . Casing 15
2 is formed in a spiral shape similar to that of the Francis turbine so that the water flowing from the inlet flange 15a passes around the rotary shaft 11 through the circumferential flow passage 14 having a gradually decreasing cross-sectional area as shown in FIG. The casing 15 is coupled to the bearing 12 via a bolt 16, and the rotating shaft 11 penetrates the casing 15 so as to be rotatable via an intermediate seal ring 17 and a seal 18 coupled to the casing 15.

Four discharge passages are formed at equal intervals along the circumference for causing water flowing in the circumferential passage 14 to fall obliquely downward from the inside of the circumferential passage 14 toward the blade 13a. That is, the inside of the casing 15 is opened downwardly over the entire circumference, and a substantially ring-shaped guide vane 19 is rotatably provided at the portion opened along the circumference and the vane retainer 20 is provided. The guide vane 19 and the circumferential flow passage 14 are prevented from coming off by the stay vane 2
1 is formed integrally with the casing 15. The guide vane 19 has one operating lever 22 in the radial direction.
Is formed, and the operation lever 22 is interlockingly connected to a servo motor (not shown). Reference numeral 23 is a discharge guide tube, and 24 is a casing boss.

Next, the stay vanes 21 and the guide vanes 1
The relationship between 9 and the runner 4 will be described based on FIG. 3 in which these members are developed along the circumference. Guide vanes 21a are formed on the stay vanes 21 to form discharge passages 21b for flowing water and four closed portions 21c for not flowing water, respectively, while guide vanes 19 are formed with guide vanes 19a for discharging water. There are formed four discharge flow channels 19b and four blocking sections 19c that do not flow water. The guide blades 19a are provided substantially parallel to the guide blades 21a, and the water discharge angle θ which is an angle formed by the guide blades 19a and the horizontal plane is set within a range of θ = 10 ° to 30 °. Setting in the range of 15 ° to 25 ° is most efficient and advantageous in construction.

Next, the operation of such an impulse turbine will be described.
Water flowing from the inlet flange 15a of FIG. 2 into the casing 15 flows in the circumferential flow passage 14 and makes four rounds around the rotary shaft 11 as shown in FIG. 2 through the four discharge flow passages 21b and 19b. It is discharged toward the blade 13a of the runner 13. That is, the water is evenly discharged from the four locations over the entire circumference of the runner 13. Then, the amount of water discharged toward the runner 13 is controlled as follows.

When the operating lever 22 is operated by a servo motor (not shown), the guide vanes 19 rotate about the rotary shaft 11. Since the stay vanes 21 are fixed in FIG.
When the closed portion 19c of the guide vane 19 overlaps 1b, the discharge flow path is closed, and water does not flow toward the runner 13. When the discharge flow path 21b of the guide vane 19 completely overlaps the discharge flow path 21b of the stay vane 21, the discharge flow path is in a fully opened state, and the runner 13 reaches the maximum rotation speed. By rotating the guide vane 19 by the width L of the discharge passage 21b, the amount of water flowing toward the runner 13 can be changed from 0 to the maximum value.

As shown in FIG. 1, assuming that the width of the discharge flow passage 19b of the guide vane 19 is B, as shown in FIG. 3, the discharge flow passage 19b and the closed portion 19c occupy approximately half and half. The area S of the portion where the water flows is S = B × πD × (1/2), and the flow rate Q ₂ of the water flowing to the runner 13 is Q ₂ = B × πD × (1 / 2) × V. When B = d is set here, B = D /
It can be replaced with 4.5. The flow rate Q ₂ is θ
= 90 °, the maximum value is obtained, and Q ₂ is proportional to sin θ. Therefore, when θ = 25 °, for example, Q ₂ = (D / 4.5) × πD × (1/2) × V × sin
25 ° ≈0.14D ² V (2) As can be seen by comparing equation (2) with equation (1) above, the flow rate is 1.8 times the flow rate of water in the conventional impulse turbine. When the runners of the same size are used, the width B of the discharge flow passage 19b of the guide vane 19 can be made larger in the impulse turbine of the present invention than the inner diameter dimension d of the conventional nozzle, and B = 1. Since it can be set to _{1 to} 1.2 d, Q ₂ = (0.14 / 0.07757) Q ₁ × 1.2 ≈2.16Q ₁ . That is, the impulse turbine according to the present invention can flow twice or more the amount of water to the runner as compared with the conventional impulse turbine, and the efficiency is improved accordingly.

In this embodiment, the rotary shaft has a vertical axis extending in the vertical direction, but the rotary shaft may be extended horizontally to form a horizontal axis. Further, in the present embodiment, four discharge channels are formed along the circumference, but the number is not limited to this and can be arbitrarily selected.

[0020]

As can be seen from the above description, according to the impulse turbine of the present invention, water is jetted to the runner through the circumferential flow passage and the discharge flow passage, so that the water is jetted over the entire circumference of the runner. As a result, it is possible to inject water into the runner at a flow rate more than twice that of the conventional impulse turbine. Therefore, a high output impulse turbine can be obtained.

Further, the fact that the output is increased means that the impulse turbine can be downsized by making the outputs the same, and the installation area of the impulse turbine can be made small. Moreover, the fact that it can be made smaller also means that it can be rotated at a higher speed, so the number of poles of the generator can be reduced, and the generator can be a low-cost small-sized one.

Furthermore, since water is sprayed over substantially the entire circumference of the runner, a load is evenly applied to the axial center of the runner, and the strength of the bearing or the like for supporting the rotary shaft can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of an impulse turbine according to the present invention.

FIG. 2 is a plan view showing an embodiment of an impulse turbine according to the present invention.

FIG. 3 is a development view of a casing and the like according to the embodiment of the impulse turbine according to the present invention.

FIG. 4 is a plan view of a conventional impulse turbine.

[Explanation of symbols]

 11 ... Rotating shaft 12 ... Bearing 13 ... Runner 14 ... Circular flow path 19 ... Guide vane 21 ... Stay vane 19b, 21b ... Discharge flow path

Claims (1)

[Claims] 1. A runner is fixed to a rotary shaft that is rotatably supported via bearings, a circumferential flow path is formed so that falling water flows around the rotary shaft, and water flowing in the circumferential flow path is directed to the runner. An impulse turbine, characterized in that discharge channels for discharging toward each other are formed at substantially equal intervals around a rotation axis.